Centrifugal blowers are commonly used for directing a forced flow of air through an air duct. In a typical blower assembly, air is drawn into a housing through an air inlet and discharged from the housing through an air outlet. Blower assemblies typically include an electrically driven blower wheel that rotates in a predetermined direction in the housing. The blower wheel includes one or more arcuate blades, which draw the air into the blower wheel axially along an axis of rotation and discharge the air radially outwardly therefrom.
Typically, in climate control applications such as heating, ventilating, and air conditioning (HVAC) systems of a vehicle, the centrifugal blowers are required to operate effectively and efficiently over a range of operating conditions of the vehicle. However, current centrifugal blowers may produce an undesirable level of noise, vibration, and harshness (“NVH”) caused by, for example, motor cogging torque and axial cogging forces, torque ripple, and axial ripple forces which excite vibration and resonant modes in the blower wheel structure.
Accordingly, it would be desirable to produce a blower wheel that maximizes performance and structural integrity, while minimizing a cost and optimizing modes of vibration thereof.